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PubMed2001

The need for psychosocial support in parents with cochlear implanted children.

OBJECTIVE: The aim of the study was to assess the need of parents with Cochlear implanted children for psychosocial support, based on psychic symptoms reported by these parents and their motivation to make use of psychosocial interventions. METHODS: Fifty seven mothers and 46 fathers of 57 Cochlear implanted children were evaluated separately, employing validated questionnaires (Symptom Checklist-90-R and Questionnaire on Psychosocial Support). RESULTS: 26% of the mothers and 25% of the fathers showed severe psychic symptoms as reflected in the Symptom Checklist-90-R. Fifty nine percent of the mothers and 60% of the fathers were highly motivated to participate in psychosocial interventions--especially in the form of further information on their children's ailment and in parents' groups. CONCLUSIONS: The data presented suggest that there is a need for psychosocial support in 18% of the parents; 8% of the parents show high psychic stress, but low motivation. The rest of the parents are not in need of support; nevertheless, 42% of the parents are highly motivated in favor of psychosocial interventions.

Adult↗

PubMed1995

Misleading the deaf community about cochlear implantation in children.

Activists are misleading the deaf community in an effort to generate opposition to cochlear implants in children. Their methods include both misinformation and the use of inflammatory, illogical rhetoric. To date they have been successful in causing anger, frustration, and overt violence among the culturally deaf with the use of such terms as "genocide" and "child abuse." Because the average reading level of a deaf residential high school graduate is at the third or fourth grade level, a small elite is able to control the interpretation and flow of complex information to many deaf people. It is a challenge to make accurate information, both positive and negative, accessible directly to deaf society. Just as the deaf have abandoned opposition to cochlear implants in adults, the same might be expected to occur in children when they and their parents become aware of the results of implantation.

Age Factors↗

PubMed1992

[Cochlear implants in children].

The development of surgically implantable hearing aids that are placed directly in the cochlea where they send electrical impulses to the cochlear nerve is a major break-through for patients whose hearing loss is so severe as to make conventional electroacoustic hearing aids ineffectual. Initially used only in adults, this method has gradually been extended to pediatric patients. To benefit from a cochlear implant, the patient must fulfill a number of criteria which are specified in this article. Following preoperative investigations, the decision is taken during a meeting of all the care providers involved, i.e., the surgeon, ENT phoniatrist or audiophonologist, hearing aid specialist, special education provider, speech therapist, psychologist, and other members of the health care staff. Team work is thus essential both before and after the procedure. The implant selected can be intracochlear or extracochlear and single-channel (one electrode) or multi-channel (several electrodes). Each team selects the implantation technique and type of implant they use according to their preferences and specific criteria. The authors use a multi-channel intracochlear system except in the rare instances where complete ossification of the cochlea requires use of an intracochlear mono-channel system. They have inserted implants in 29 patients to date. The cochlear implant has unquestionably had a significant impact of the life of these patients.

Child↗

PubMed2001

Use of audiovisual information in speech perception by prelingually deaf children with cochlear implants: a first report.

OBJECTIVE: Although there has been a great deal of recent empirical work and new theoretical interest in audiovisual speech perception in both normal-hearing and hearing-impaired adults, relatively little is known about the development of these abilities and skills in deaf children with cochlear implants. This study examined how prelingually deafened children combine visual information available in the talker's face with auditory speech cues provided by their cochlear implants to enhance spoken language comprehension. DESIGN: Twenty-seven hearing-impaired children who use cochlear implants identified spoken sentences presented under auditory-alone and audiovisual conditions. Five additional measures of spoken word recognition performance were used to assess auditory-alone speech perception skills. A measure of speech intelligibility was also obtained to assess the speech production abilities of these children. RESULTS: A measure of audiovisual gain, "Ra," was computed using sentence recognition scores in auditory-alone and audiovisual conditions. Another measure of audiovisual gain, "Rv," was computed using scores in visual-alone and audiovisual conditions. The results indicated that children who were better at recognizing isolated spoken words through listening alone were also better at combining the complementary sensory information about speech articulation available under audiovisual stimulation. In addition, we found that children who received more benefit from audiovisual presentation also produced more intelligible speech, suggesting a close link between speech perception and production and a common underlying linguistic basis for audiovisual enhancement effects. Finally, an examination of the distribution of children enrolled in Oral Communication (OC) and Total Communication (TC) indicated that OC children tended to score higher on measures of audiovisual gain, spoken word recognition, and speech intelligibility. CONCLUSIONS: The relationships observed between auditory-alone speech perception, audiovisual benefit, and speech intelligibility indicate that these abilities are not based on independent language skills, but instead reflect a common source of linguistic knowledge, used in both perception and production, that is based on the dynamic, articulatory motions of the vocal tract. The effects of communication mode demonstrate the important contribution of early sensory experience to perceptual development, specifically, language acquisition and the use of phonological processing skills. Intervention and treatment programs that aim to increase receptive and productive spoken language skills, therefore, may wish to emphasize the inherent cross-correlations that exist between auditory and visual sources of information in speech perception.

Acoustic Stimulation↗

PubMed1993

Parental expectations as a factor in evaluating children for the multichannel cochlear implant.

Recent developments in technology have resulted in a new assistive device for profoundly deaf children: the cochlear implant. However, many variables must be considered when evaluating children for the device, one of which is parental expectations. Because expectations are sometimes unreasonable high, cochlear implant teams need to be aware of the dynamics involved in expectations and of ways to help parents come to a realistic understanding of the benefits and limitations of implants.

Adolescent↗

PubMed1993

Speech encoding strategies for multielectrode cochlear implants: a digital signal processor approach.

The following processing strategies have been implemented on an experimental laboratory system of a cochlear implant digital speech processor (CIDSP) for the Nucleus 22-channel cochlear prosthesis. The first approach (PES, Pitch Excited Sampler) is based on the maximum peak channel vocoder concept whereby the time-varying spectral energy of a number of frequency bands is transformed into electrical stimulation parameters for up to 22 electrodes. The pulse rate at any electrode is controlled by the voice pitch of the input speech signal. The second approach (CIS, Continuous Interleaved Sampler) uses a stimulation pulse rate which is independent of the input signal. The algorithm continuously scans all specified frequency bands (typically between four and 22) and samples their energy levels. As only one electrode can be stimulated at any instance of time, the maximally achievable rate of stimulation is limited by the required stimulus pulse widths (determined individually for each subject) and some additional constraints and parameters. A number of variations of the CIS approach have, therefore, been implemented which either maximize the number of quasi-simultaneous stimulation channels or the pulse rate on a reduced number of electrodes. Evaluation experiments with five experienced cochlear implant users showed significantly better performance in consonant identification tests with the new processing strategies than with the subjects' own wearable speech processors; improvements in vowel identification tasks were rarely observed. Modifications of the basic PES- and CIS strategies resulted in large variations of identification scores. Information transmission analysis of confusion matrices revealed a rather complex pattern across conditions and speech features. Optimization and fine-tuning of processing parameters for these coding strategies will require more data both from speech identification and discrimination evaluations and from psychophysical experiments.

Acoustic Stimulation↗

PubMed2003

Effects of simulated cochlear-implant processing on speech reception in fluctuating maskers.

This study investigated the effects of simulated cochlear-implant processing on speech reception in a variety of complex masking situations. Speech recognition was measured as a function of target-to-masker ratio, processing condition (4, 8, 24 channels, and unprocessed) and masker type (speech-shaped noise, amplitude-modulated speech-shaped noise, single male talker, and single female talker). The results showed that simulated implant processing was more detrimental to speech reception in fluctuating interference than in steady-state noise. Performance in the 24-channel processing condition was substantially poorer than in the unprocessed condition, despite the comparable representation of the spectral envelope. The detrimental effects of simulated implant processing in fluctuating maskers, even with large numbers of channels, may be due to the reduction in the pitch cues used in sound source segregation, which are normally carried by the peripherally resolved low-frequency harmonics and the temporal fine structure. The results suggest that using steady-state noise to test speech intelligibility may underestimate the difficulties experienced by cochlear-implant users in fluctuating acoustic backgrounds.

Acoustic Stimulation↗

PubMed1991

Analysis of the spontaneous speech samples of children with cochlear implants or tactile aids.

Analyses were performed on the spontaneous speech samples produced by profoundly hearing-impaired children who used the 3M/House single-channel cochlear implant (n = 7), the Nucleus multichannel cochlear implant (n = 7), or the two-channel tactile aid, the Tactaid II (n = 12). Speech recordings were obtained in the predevice condition, and after 6- and 12-months use. The speech of the children in the three experimental groups was compared to that of a control group of subjects who used a tactile aid inconsistently and received minimal speech training. Several new analysis procedures were developed to describe adequately the characteristics of the children's speech. The results revealed that all three experimental groups and the control group showed an increase in their production of sounds classified as English phonemes in the postdevice conditions. It was apparent at both the 6- and 12-months postdevice intervals that the most dramatic improvements were made by the users of the Nucleus device. The changes made by the Tactaid and 3M/House users were similar. The subjects with the Nucleus device also developed more diverse phonetic repertoires over time than did the other experimental subjects. More subjects with the Nucleus device acquired fricatives, liquids, glides, voiceless consonants, and high front vowels than did the subjects in the other groups. The subjects in the control group developed the most limited phonetic repertoires.

Auditory Threshold↗

PubMed2005

Histopathology of human cochlear implants: correlation of psychophysical and anatomical measures.

The cadavaric temporal bones of five subjects who underwent cochlear implantation during life (2 Nucleus and 3 Ineraid) were analyzed using two-dimensional (2D) reconstruction of serial sections to determine the number of surviving spiral ganglion cells (SGCs) in the region of each electrode of the implanted arrays. The last psychophysical threshold and maximum-comfortable sensation level measured for each electrode were compared to their respective SGC count to determine the across-electrode psychophysical variance accounted for by the SGC counts. Significant correlations between psychophysical measures and SGC counts were found in only two of the five subjects: one Nucleus implantee (e.g., r=-0.71; p<0.001 for threshold vs. count) and one Ineraid implantee (e.g., r=-0.86; p<0.05 for threshold vs. count). A three-dimensional (3D) model of the implanted cochlea was formulated using the temporal-bone anatomy of the Nucleus subject for whom the 2D analysis did not result in significant correlations between counts and psychophysical measures. Predictions of the threshold vs. electrode profile were closer to the measured profile for the 3D model than for the 2D analysis. These results lead us to hypothesize that 3D techniques will be required to asses the impact of peripheral anatomy on the benefit patients derive from cochlear implantation.

Cadaver↗

PubMed1998

Comprehension of language in congenitally deaf children with and without cochlear implants.

The consequences of profound early deafness on oral language in children are drastic. The modern cochlear implant (CI) has been shown to enhance speech production skills in prelingually deaf children. Many factors may contribute to a poor or an excellent outcome, making it difficult to compare groups of children wearing or not wearing cochlear implants. The present study compared receptive language levels in matched pairs of children from CI group and non-CI groups. The pre-op receptive language development curve suggest a possible growth over time with the maturation and the speech therapy. Comparison showed that the slope for post-op CI children to be greater than for non-CI children, and that this difference is statistically significant, and that the slope for CI children to be greater post- than pre-operatively. The main conclusion is that receptive language scores grow significantly higher over time after surgery in CI than in pair-matched non-CI children, despite better initial pure tone audiometric thresholds of the latter.

Age Factors↗

PubMed2006

The multiple-channel cochlear implant: the interface between sound and the central nervous system for hearing, speech, and language in deaf people-a personal perspective.

The multiple-channel cochlear implant is the first sensori-neural prosthesis to effectively and safely bring electronic technology into a direct physiological relation with the central nervous system and human consciousness, and to give speech perception to severely-profoundly deaf people and spoken language to children. Research showed that the place and temporal coding of sound frequencies could be partly replicated by multiple-channel stimulation of the auditory nerve. This required safety studies on how to prevent the effects to the cochlea of trauma, electrical stimuli, biomaterials and middle ear infection. The mechanical properties of an array and mode of stimulation for the place coding of speech frequencies were determined. A fully implantable receiver-stimulator was developed, as well as the procedures for the clinical assessment of deaf people, and the surgical placement of the device. The perception of electrically coded sounds was determined, and a speech processing strategy discovered that enabled late-deafened adults to comprehend running speech. The brain processing systems for patterns of electrical stimuli reproducing speech were elucidated. The research was developed industrially, and improvements in speech processing made through presenting additional speech frequencies by place coding. Finally, the importance of the multiple-channel cochlear implant for early deafened children was established.

Cochlear Implants↗

PubMed1995

Surgical difficulties and postoperative problems associated with cochlear implants.

Since 1987 we have implanted 60 severely hearing-impaired adults with the Nucleus Minisystem-22 cochlear implant. In most cases, the surgical procedures were performed with satisfactory results and very few postoperative problems. The complications associated with cochlear implant surgery include difficulty in drilling the ossified cochlea, electrode displacement, and insufficient insertion of the electrode. Postoperative problems include dizziness, tinnitus, facial nerve spasm, receiver-stimulator migration or extrusion, infection of the scalp flap, and facial nerve palsy. In most cases, these complaints did not develop into serious conditions.

Adult↗

PubMed1993

Demographic and audiological profiles of deaf children in Texas with cochlear implants.

This paper reports the findings of a study that examined the demographic, educational, and audiological characteristics of a sample of children in Texas who had received cochlear implants. Children who had received implants and children who had not were compared. Differences between the two groups are discussed in the context of the criteria that have been published in the literature for selecting implant candidates. Results indicate that although the published selection criteria were predictive of the characteristics of the implanted sample, there was a degree of flexibility in applying the criteria to choose implant recipients. Audiological comparisons revealed that cochlear implant recipients experience greater reductions in average hearing thresholds than do users of conventional aids, although these findings should be viewed as preliminary.

Achievement↗

PubMed1986

Radiographic imaging of the cochlear implant candidate: preliminary results.

Preoperative radiographic imaging of the temporal bone is well accepted in otology for both the diagnosis of disease and the delineation of anatomic structure for surgical planning. Until recently radiographic techniques have unfortunately failed to demonstrate fibrous or bony obstruction of the basal turn of the cochlea, which may cause difficulties during cochlear implantation. Intraoperative findings have been correlated with preoperative imaging in a consecutive group of six cochlear implant recipients and a series of consistent radiographic signs that may indicate the presence of obstruction of the scala tympani have been identified. A classification system has been developed. Based on thin-section high-resolution computerized tomography (HRCT), the system has been used preoperatively on six cochlear implant recipients. In addition, a systematic evaluation of the temporal bone has been developed for precochlear implant evaluation. This includes the thickness of the parietal bone for seating of the receiving device, the degree of pneumatization of the mastoid, the measurement of the size of the facial recess, the description of the size and orientation of the round window niche, and the patency of the basal turn of the cochlea.

Adult↗

PubMed2004

Incidence of meningitis and of death from all causes among users of cochlear implants in the United Kingdom.

BACKGROUND: During 2002, there was an increase in reports of bacterial meningitis among people with cochlear implants in Europe and North America. One model of implant, which included a space-occupying 'positioner', was recalled. Implantation of a positioner was shown to be a risk factor for meningitis among children in the United States. The situation in the United Kingdom was not known. METHODS: We ascertained the cohort of people who had received cochlear implants with intra-cochlear electrodes in UK hospitals prior to 1 October 2002 and were permanently resident in the United Kingdom. We compared the incidence of meningitis, and the causes and incidence of death from all causes, between the cohort and reference populations. RESULTS: Of 1851 children (66 with positioners), none had contracted meningitis. Neither the incidence rate of meningitis, nor the cumulative mortality from all causes, differed significantly between implanted children and values expected for the general population. Of 1779 adults (139 with positioners), five had contracted meningitis with three fatalities. No case of meningitis involved a positioner and four of the cases, including the fatalities, possessed risk factors unrelated to implantation. Although the incidence rate of meningitis was significantly higher in implanted adults than the general population, cumulative mortality from all causes was never higher, and was significantly lower at some time points after implantation. CONCLUSION: Specific evidence of the association between bacterial meningitis and implantation with a positioner that arose in the United States and mainland Europe during 2002 has not been found in the United Kingdom.

Adolescent↗

PubMed2002

Perceptual learning following changes in the frequency-to-electrode assignment with the Nucleus-22 cochlear implant.

The goal of the present study was to investigate the time course of adaptation by experienced cochlear implant users to a shifted frequency-to-electrode assignment in their speech processors. Speech recognition performance of three Nucleus-22 cochlear implant users was measured over a 3-month period, during which the implant listeners continuously wore "experimental" speech processors that were purposely shifted by 2-4 mm in terms of the frequency-to-electrode assignment relative to their normal processor. Baseline speech performance was measured with each subject's clinically assigned speech processor just prior to implementation of the experimental processor. Baseline speech performance was measured again after the 3-month test period, immediately following the reinstallation of the clinically assigned processor settings. Speech performance with the experimental processor was measured four times during the first week, and weekly thereafter over the 3-month period. Results showed that the experimental processor produced significantly lower performance on all measures of speech recognition immediately following implementation. Over the 3-month test period, consonant and HINT sentence recognition with the experimental processors gradually approached a performance level comparable to but still significantly below the baseline and postexperiment measures made with the clinically assigned processor. However, vowel and TIMIT sentence recognition with the experimental processors remained far below the level of the baseline measures even at the end of the 3-month experimental period. There was no significant change in performance with the clinically assigned processor before or after fitting with the experimental processor. The results suggest that a long-time exposure to a new pattern of stimulation may not be able to compensate for the deficit in performance caused by a 2-4-mm shift in the tonotopic location of stimulation, at least within a 3-month period.

Adult↗

PubMed2005

Evaluation of streamlined programming procedures for the Nucleus cochlear implant with the Contour electrode array.

OBJECTIVE: The objective of this study was to evaluate streamlined programming procedures for the Nucleus cochlear implant system with the Contour electrode array. DESIGN: Phase 1 involved an examination of the clinical MAPs for the first 103 recipients implanted with the Contour electrode array in the Melbourne Cochlear Implant Clinic, to examine the ability to predict the entire MAP based on a smaller number of clinically determined T- and/or C-levels. In phase 2, a subset of the streamlined procedures was selected and clinically evaluated, using speech perception and subjective preference measures. In the first study, the clinical MAP was compared with a MAP based on interpolating across three behavioral T-levels and three behavioral C-levels in a group of newly implanted subjects. The second study investigated the use of a single interpolated profile as the basis to creating the entire MAP. Initial evaluation compared the clinical MAP with two streamlined MAPs, one in which the C-level profile was derived from interpolation across a subset of T-levels and one in which the T-level profile was derived from interpolation across a subset of C-levels. In this case, the interpolated profile was based on five behavioral measures. Subsequently, the use of either three or a single T-level measure as the basis for the interpolated T-level profile was evaluated. Eighteen subjects, who were experienced with the clinical MAP before enrollment in the study, participated in the initial evaluation. The subjects were selected to include a group whose RMS deviation from clinical MAP levels, as determined in Phase 1, was greater than that of the wider population. RESULTS: The Phase 1 analysis showed that as expected, larger differences were observed between the clinical and derived MAP levels as interpolation was applied across fewer measured electrodes and that the use of a single interpolated profile to create the entire MAP resulted in the greatest deviation. No significant group mean difference was found in speech perception scores for newly implanted subjects when mapped with the clinical versus the streamlined MAP based on three behavioral T- and three behavioral C-level measures. For some individual subjects, scores were higher with the streamlined MAP. Subjective reports from the comparative performance questionnaire were consistent with these findings. No significant group mean difference in speech perception scores was found in comparing the clinical MAP with the streamlined MAPs based on a single interpolated T- or C-level profile created from five behavioral measures. Individual effects were observed; however, there was no consistent finding across subjects. The use of three rather than five behavioral T-level measures in the procedure did not result in significantly lower group mean scores; however, significantly poorer scores were obtained for three of the 10 individual subjects. The use of a MAP based on a single behavioral measure did result in poorer speech perception scores when compared with the MAP based on five behavioral T-level measures. These findings were consistent with subjective results from the performance questionnaires administered to determine preference for program across a range of listening situations. CONCLUSIONS: Two streamlined programming procedures are recommended for use in the clinical setting: (1) interpolating across three measured T-levels and three measured C-levels and (2) interpolating across five measured T- or C-levels and using the interpolated profile for fitting of the alternative profile.

Adult↗

PubMed2004

Frequency modulation detection in cochlear implant subjects.

Frequency modulation (FM) detection was investigated in acoustic and electric hearing to characterize cochlear-implant subjects' ability to detect dynamic frequency changes and to assess the relative contributions of temporal and spectral cues to frequency processing. Difference limens were measured for frequency upward sweeps, downward sweeps, and sinusoidal FM as a function of standard frequency and modulation rate. In electric hearing, factors including electrode position and stimulation level were also studied. Electric hearing data showed that the difference limen increased monotonically as a function of standard frequency regardless of the modulation type, the modulation rate, the electrode position, and the stimulation level. In contrast, acoustic hearing data showed that the difference limen was nearly a constant as a function of standard frequency. This difference was interpreted to mean that temporal cues are used only at low standard frequencies and at low modulation rates. At higher standard frequencies and modulation rates, the reliance on the place cue is increased, accounting for the better performance in acoustic hearing than for electric hearing with single-electrode stimulation. The present data suggest a speech processing strategy that encodes slow frequency changes using lower stimulation rates than those typically employed by contemporary cochlear-implant speech processors.

Adult↗